CN115021073A - A high-power silicon-based semiconductor laser based on apodized gratings - Google Patents

Abstract

The invention relates to a high-power silicon-based semiconductor laser based on apodization grating, comprising: a substrate, a buried oxide layer, a waveguide layer, an auxiliary bonding layer, a spacer layer, a cladding layer, a quantum well active region, and a top cladding layer, ohmic contact layer, P-type electrode, and N-type electrode; an apodized grating is etched in the waveguide layer along the cavity length direction of the resonant cavity; the invention adopts the design of the apodized grating, and the photon density at both ends of the laser cavity has asymmetry , the output optical power and utilization efficiency are significantly improved, while ensuring stable single-mode output, it effectively solves the problem of low output optical power/efficiency of the λ/4 phase-shift laser. Compared with the λ/4 phase-shift laser, the resonant cavity based on the apodized grating of the present invention has a more gentle distribution of the light field in the cavity, so as to solve the influence of the spatial hole burning of the λ/4 phase-shift laser and obtain better laser performance. .

Description

A high-power silicon-based semiconductor laser based on apodized gratings

technical field

The invention relates to a high-power silicon-based semiconductor laser based on an apodized grating, belonging to the technical field of optoelectronics.

Background technique

With the application of silicon photonics integration technology in the fields of high-speed optical communication, big data, and high-efficiency computing, the realization of high-efficiency silicon photonics integrated light sources has become the focus of attention. Since silicon is an indirect band gap semiconductor material, there are free carrier absorption, Auger recombination and indirect recombination effects, and the light radiation efficiency is extremely low, making it difficult to prepare a laser light source. At present, the advantages of high refractive index difference of SOI material and high gain of III-V material can be combined by using wafer bonding technology to adhere the direct bandgap III-V semiconductor gain material above the silicon-on-insulator (SOI) waveguide. , has become one of the mainstream solutions for making silicon-based lasers.

Distributed feedback lasers (DFB-LDs) are widely used in III-V/SOI hybrid integration platforms because they can achieve stable single-mode output in a certain current range and temperature range. Generally, for a DFB laser with a uniform grating, when the reflectivity of the cavity surfaces at both ends of the laser is 0, there are two merged longitudinal modes on both sides of the Bragg wavelength, and single-mode output cannot be achieved. In the traditional III-V DFB laser, the reflection and random phase of the end face can be introduced by coating both ends of the cavity, which can eliminate the mode merger problem to a certain extent and realize the single-mode output of the laser. However, when applied to III-V/SOI hybrid integration, it is difficult to cut the laser and coat the end faces, so silicon-based III-V DFB lasers usually introduce a quarter-wavelength (λ/4) phase shift in the center of the cavity. The mode of the region realizes the single-mode output of the laser. This λ/4 phase-shift laser has the lowest threshold gain at the Bragg wavelength, can form a stable single-mode output, and benefits from the mature CMOS (Complementary Metal Oxide Semiconductor) process, compared to III -V group DFB laser can greatly reduce the difficulty of making gratings. However, due to the symmetry of the cavity, the output power of the light at both ends of the cavity is equal, and usually only the output light of one end can be used, which leads to the low output optical power and utilization efficiency of the laser, and the optical field in the cavity of the λ/4 phase-shift laser is mostly Concentrating on the central position of the cavity easily leads to severe vertical space hole burning effect, which limits the performance of the laser to a certain extent.

SUMMARY OF THE INVENTION

The invention adopts the apodized grating, so that the light output at both ends of the resonator has asymmetry, the output optical power and utilization efficiency are obviously improved, and the output optical power and utilization efficiency of the λ/4 phase-shift laser are effectively solved while ensuring stable single-mode output. low problem.

Compared with the λ/4 phase-shift laser, the laser resonator of the present invention has a smoother intra-cavity optical field distribution, which can effectively reduce the space hole burning problem of the λ/4 phase-shift laser and obtain better laser performance.

Terminology Explanation:

1. Grating coupling coefficient. The periodic corrugated structure of the grating can generate distributed mutual coupling between the forward and backward waves that originally propagated independently along the cavity length direction. The grating coupling coefficient can characterize the feedback strength of the grating, that is, the forward , the coupling strength between the backward light is an important parameter of the DFB laser, and the expression is as follows:

表示光栅同一周期中高折射率部分和低折射率部分的有效折射率，λ₀为布拉格波长。where D represents the duty cycle,

represents the effective refractive index of the high refractive index part and the low refractive index part in the same period of the grating, and λ ₀ is the Bragg wavelength.

2. Effective refractive index, the effective refractive index is used to describe the amount of phase retardation per unit length in the waveguide relative to the phase retardation per unit length in vacuum, and is defined as n _eff =β/k ₀ . Among them, β refers to the propagation constant of light wave, which is described as the phase change of light propagating unit distance in medium or waveguide; k ₀ is the vacuum wave number.

3. The molecular bonding technology of the silicon dioxide dielectric layer refers to the molecular bonding technology that uses the _SiO2 dielectric layer as the bonding interface.

The main principle of the bonding technology is to adhere the III-V direct bandgap semiconductor material on the SOI silicon waveguide by bonding technology, which can avoid the problem of lattice mismatch in heteroepitaxial growth, and the process is simple and can be highly integrated. , so it has a very good application prospect. According to the different bonding materials, four different bonding technologies can be used to prepare hybrid integrated single-mode silicon-based lasers for silicon photonic interconnection: Flip-chip bonding technology, direct molecular bonding technology, SiO ₂ dielectric layer molecules Bonding technology, DVS-BCB bonding technology.

The direct molecular bonding technique generates H ₂ and H ₂ O during its bonding process, resulting in the existence of air bubbles inside the bonding layer, thus reducing the bonding quality and yield. The SiO ₂ dielectric layer molecular bonding technology can effectively solve the problem of auxiliary gas generated during the bonding process, improve the bonding quality, and improve the coupling efficiency between the gain region and the silicon waveguide.

The technical scheme of the present invention is:

A high-power silicon-based semiconductor laser based on apodization grating, comprising: substrate, buried oxide layer, waveguide layer, auxiliary bonding layer, spacer layer, cladding layer, quantum well active region, top cladding layer, ohmic layer Contact layer, P-type electrode, N-type electrode;

An apodized grating is etched in the waveguide layer along the cavity length direction of the resonant cavity;

By modulating the lateral width of the apodized grating, the effective refractive index of the resonant cavity and the coupling coefficient of the grating are changed along the cavity length direction of the resonant cavity.

从而选择光栅的有效折射率n_eff和光栅耦合系数k；

D表示占空比，λ₀为布拉格波长。Further preferably, by modulating the transverse width of the apodized grating, the effective refractive index of the resonant cavity and the coupling coefficient of the grating are changed along the cavity length direction of the resonant cavity, and the low refractive index part of the grating is selected by adjusting and selecting an appropriate transverse width of the grating. and the effective refractive index of the high refractive index part

Thus, the effective refractive index n _eff of the grating and the coupling coefficient k of the grating are selected;

D represents the duty cycle, and λ ₀ is the Bragg wavelength.

Preferably according to the present invention, the resonant cavity is divided into a first uniform area, an apodization area and a second uniform area in sequence from left to right. In the first uniform area and the second uniform area, the grating coupling coefficient and effective refractive index remain unchanged ; In the apodized region, the grating coupling coefficient and effective refractive index change linearly.

Further preferably, set the effective refractive index of the first uniform region as n _eff1 , and the grating coupling coefficient k ₁ ; the effective refractive index of the second uniform region is n _eff2 , the grating coupling coefficient k ₂ ; the grating coupling coefficient of the apodized region is from k ₁ to k ₂ Linear change, the effective refractive index changes linearly from n _eff1 to n _eff2 ;

Assuming that the lengths of the first uniform region, the apodized region, and the second uniform region are l ₁ , l ₂ , and l ₃ respectively, and the distance from a certain position of the apodized region to the leftmost end of the resonator is z, 0<z<l ₁ +l ₂ +l ₃ , the apodized region grating coupling coefficient distribution k(z) and effective refractive index distribution n _eff (z) are expressed as equations (I) and (II):

The optimal n _eff1 , n _eff2 , k ₁ , and k ₂ are determined through simulation, so that the output light can obtain the highest SMSR, the highest output optical power and a smooth light field distribution.

Preferably according to the present invention, the total length of the apodized grating along the cavity length direction of the resonant cavity is 300-1000 μm, the length of the first uniform region along the cavity length direction of the resonant cavity is 200-900 μm, and the apodized region along the cavity length direction of the resonant cavity is 200-900 μm. The length in the long direction is 5-50 μm, and the length of the second uniform region along the cavity length direction of the resonant cavity is 30-200 μm.

Preferably according to the present invention, the duty cycle of the apodized grating is 0.4-0.6.

Preferably according to the present invention, the grating width W ₁ of the apodized grating is 0-2 μm, and the grating width W ₂ of the apodized grating is 0.3-7 μm; the grating width W ₁ refers to the width of the low refractive index portion of the grating; the grating width W ₂ is the width of the high refractive index portion of the grating.

Further preferably, the total length of the apodized grating along the cavity length direction of the resonant cavity is 500 μm, the length of the first uniform region along the cavity length direction of the resonant cavity is 410 μm, and the length of the apodized grating along the cavity length direction of the resonant cavity is 20 μm. , the length of the second uniform region along the cavity length direction of the resonator is 70 μm; the grating period of the apodized grating is 240.3 nm, and the duty cycle of the apodized grating is 0.5; the grating width W1 _of the apodized grating is 0-2 μm, The grating width W ₂ of the apodized grating takes 0.3-7 μm.

Preferably according to the present invention, an apodized grating is etched in the waveguide layer along the cavity length direction of the resonant cavity, including:

First, a layer of photolithography mask is deposited on the surface of the waveguide layer, and photolithography is performed to form a patterned structure; then, dry etching is performed to form a first etching depth grating structure;

Next, photolithography and dry etching are performed in sequence to form a second etching depth grating structure;

Finally, photolithography and dry etching are sequentially performed until the buried oxide layer is etched to form a strip waveguide.

Preferably according to the present invention, the material of the substrate is Si; the material of the buried oxide layer is SiO ₂ , and the thickness is 0.5-3 μm; the material of the waveguide layer is Si, and the thickness is 220-500 nm; The auxiliary bonding layer is made of SiO ₂ with a thickness of 0-300 nm; the spacer layer is made of InP with a thickness of 10-200 nm; the cladding layer is made of SiO ₂ and has a thickness of 200-3000 nm; the quantum The material of the well active region is InAlGaAs or InGaAsP, the thickness is 300-600nm, and the width is 1.5-10μm; the material of the top cladding layer is InP, the thickness is 1.4-1.8μm, the top width is 1.5-10μm, and the bottom end is 1.5-10μm. The width is 1.5-9 μm; the material of the ohmic contact layer is InGaAs, and the thickness is 150nm; the material of the P-type electrode is TiPtAu-Au or Ti/Al, and the thickness is 200-4000nm; the material of the N-type electrode is TiPtAu-Au or Ti/Al with a thickness of 200-4000nm.

Further preferably, the thickness of the substrate is 750 μm; the thickness of the buried oxide layer is 1000 nm; the thickness of the waveguide layer is 400 nm; the thickness of the auxiliary bonding layer is 70 nm; the thickness of the spacer layer is 150 nm; the thickness of the cladding layer is 2000 nm; the thickness of the quantum well active region is 400 nm and the width is 7 μm, and the quantum well active region includes three well layers and four barrier layers, which are arranged in a cross, each The thickness of each well layer is 7 nm, and the thickness of each barrier layer is 9 nm; the thickness of the top cladding layer is 1.6 μm, the top width is 4 μm, and the bottom width is 2.5 μm; the thickness of the ohmic contact layer is 150 nm; The thickness of the P-type electrode is 2000 nm; the thickness of the N-type electrode is 2000 nm.

The beneficial effects of the present invention are:

The invention combines the advantages of the high luminous efficiency of the III-V gain chip and the high integration and high transmission capacity of the SOI silicon optical chip. At the same time, through the design of the apodized grating, the photon density at both ends of the laser cavity has asymmetry, and the output optical power and utilization efficiency are significantly improved. While ensuring stable single-mode output, the output power/efficiency of the λ/4 phase-shifted laser can be effectively solved. low problem. Compared with the λ/4 phase-shift laser, the resonant cavity based on the apodized grating of the present invention has a more gentle distribution of the light field in the cavity, so as to solve the influence of the spatial hole burning of the λ/4 phase-shift laser and obtain better laser performance. .

Description of drawings

1 is a schematic structural diagram of a high-power silicon-based semiconductor laser based on apodized gratings of the present invention;

Fig. 2 is the schematic diagram of apodized grating of the present invention;

3 is a schematic diagram of a lasing spectrum of a high-power silicon-based semiconductor laser based on apodized gratings of the present invention;

Fig. 4 is a schematic diagram of normalized intracavity photon concentration;

FIG. 5 is a schematic diagram of the LI curve of the high-power silicon-based semiconductor laser based on the apodized grating of the present invention.

1. Substrate, 2. Buried oxide layer, 3. Waveguide layer, 4. Auxiliary bonding layer, 5. Spacer layer, 6. Cladding layer, 7. Quantum well active region, 8. Top cladding layer, 9 , Ohmic contact layer, 10, P-type electrode, 11, N-type electrode.

Detailed ways

The present invention is further defined below with reference to the accompanying drawings and embodiments of the description, but is not limited thereto.

Example 1

A high-power silicon-based semiconductor laser based on an apodized grating, as shown in Figure 1, includes: a substrate 1, a buried oxide layer 2, a waveguide layer 3, an auxiliary bonding layer 4, a spacer layer 5, a cladding layer 6, Quantum well active region 7, top cladding layer 8, ohmic contact layer 9, P-type electrode 10, N-type electrode 11;

In the waveguide layer 3, an apodized grating is etched along the cavity length direction of the resonant cavity; including: the apodized grating is processed by a standard silicon photonics CMOS process, which is generally etched in three steps: first, deposit a Layer lithography mask, use high-precision lithography equipment to perform lithography to form a patterned structure; then, perform dry etching to form a first etching depth grating structure; secondly, perform photolithography and dry etching in sequence to form The second etching depth grating structure; finally, photolithography and dry etching are sequentially performed until the etching is carried out to the buried oxide layer 2 to form a strip waveguide.

By modulating the lateral width of the apodized grating, the effective refractive index of the resonant cavity and the coupling coefficient of the grating are changed along the cavity length direction of the resonant cavity.

Example 2

A high-power silicon-based semiconductor laser based on an apodized grating according to Embodiment 1, the difference is:

从而选择光栅总体的有效折射率n_eff和光栅耦合系数k；

D表示占空比，λ₀为布拉格波长。By modulating the lateral width of the apodized grating, the effective refractive index of the resonator and the coupling coefficient of the grating change along the cavity length of the resonator. The effective refractive index of the waveguide mode is related to the size of the waveguide. Through the finite difference method simulation, a specific waveguide can be obtained. The effective refractive index of the waveguide mode under the size, therefore, the effective refractive index of the low-refractive index part and the high-refractive index part of the grating can be selected by adjusting and selecting the appropriate lateral width of the grating

Thereby, the effective refractive index n _eff of the grating and the coupling coefficient k of the grating are selected;

D represents the duty cycle, and λ ₀ is the Bragg wavelength.

The invention introduces the relative phase shift through the change of the effective refractive index, which can change the threshold gain difference between the fundamental modes on both sides of the stop band and the threshold gain difference between the fundamental mode and the high-order mode, thereby breaking the double-mode degeneracy phenomenon and obtaining the first choice. lasing mode. Using the above-mentioned apodized grating to realize the single-mode operation of the laser, compared with the λ/4 phase-shift laser, the optical field distribution in the cavity is smoother, and the spatial hole burning effect is effectively reduced. In the present invention, the distribution of photon density and carrier density in the cavity can be changed by designing the grating coupling coefficient along the cavity length direction, so that the longitudinal distribution of the cavity becomes asymmetric, so that the photon density near the output end is larger. , thereby increasing the laser output optical power.

The invention combines the advantages of the high luminous efficiency of the III-V gain chip and the high integration and high transmission capacity of the SOI silicon optical chip. At the same time, through the design of the apodized grating, the photon density at both ends of the laser cavity has asymmetry, and the output optical power and utilization efficiency are significantly improved. While ensuring stable single-mode output, the output power/efficiency of the λ/4 phase-shifted laser can be effectively solved. low problem. Secondly, compared with the λ/4 phase-shift laser, the resonant cavity based on the apodized grating in the present invention has a smoother intra-cavity optical field distribution, so as to solve the influence of the spatial hole burning of the λ/4 phase-shift laser, and obtain better results. laser performance.

Example 3

A high-power silicon-based semiconductor laser based on an apodized grating according to Embodiment 1, the difference is:

As shown in Figure 2, the resonant cavity is divided into a first uniform area, an apodization area, and a second uniform area from left to right. In the first uniform area and the second uniform area, the grating coupling coefficient and effective refractive index remain unchanged. ; By controlling the lateral width of the grating in this region, the lateral width of the grating remains the same along the cavity length direction, so that the grating coupling coefficient and effective refractive index remain unchanged; in the apodized region, the grating coupling coefficient and effective refractive index change linearly. By controlling the lateral width of the grating in this region, the grating coupling coefficient and effective refractive index change linearly along the cavity length direction, and the specific width changes are determined by simulation.

Let the effective refractive index of the first uniform region be n _eff1 , the grating coupling coefficient k ₁ ; the effective refractive index of the second uniform region be n _eff2 , the grating coupling coefficient k ₂ ; the grating coupling coefficient of the apodized region changes linearly from k ₁ to k ₂ , The effective refractive index varies linearly from n _eff1 to n _eff2 ;

Assuming that the lengths of the first uniform region, the apodized region, and the second uniform region are l ₁ , l ₂ , and l ₃ respectively, and the distance from a certain position of the apodized region to the leftmost end of the resonator is z, 0<z<l ₁ +l ₂ +l ₃ , the apodized region grating coupling coefficient distribution k(z) and effective refractive index distribution n _eff (z) are expressed as equations (I) and (II):

The optimal n _eff1 , n _eff2 , k ₁ , and k ₂ are determined through simulation, so that the output light can obtain the highest SMSR, the highest output optical power and a smooth light field distribution. The simulation results are shown in Figure 3, Figure 4 and Figure 5.

The apodized grating of this embodiment will introduce a refractive index change in the cavity to generate an equivalent phase shift, thereby breaking the double-mode degeneracy phenomenon existing in the DFB laser and achieving the purpose of single-mode output of the laser. The laser output spectrum is shown in Figure 3.

Since the grating coupling coefficient is not uniformly distributed, the optical field distribution in the resonator is not uniform. When the coupling coefficient of the grating in the apodized region is greater than the first uniform region, more photons in the cavity will be distributed at the left end of the resonator, as shown in Figure 4, so that the optical power obtained at the output of the resonator is increased and the output is improved. light utilization efficiency. At the same time, it can be seen from Figure 4 that, compared with the traditional λ/4 phase-shifted laser, the resonator structure based on the apodized grating design has a smoother optical field distribution in the cavity, which can effectively suppress the spatial hole burning effect.

The LI curve of the laser of this embodiment is shown in FIG. 5 . Compared with the λ/4 phase-shifted laser with equal threshold in the same situation, the optical output power of this embodiment is obviously improved.

Example 4

A high-power silicon-based semiconductor laser based on an apodized grating according to Embodiment 1, the difference is:

The total length of the apodized grating along the cavity length of the resonator is 300-1000 μm, the length of the first uniform region along the cavity length of the resonator is 200-900 μm, and the length of the apodized region along the cavity length of the resonator is 5 -50 μm, the length of the second uniform region along the cavity length direction of the resonant cavity is 30-200 μm.

According to the above settings of the cavity length and the length of each region, the optimal laser performance can be obtained, such as higher output power and good single-mode performance.

The grating period of the apodized grating is designed according to the laser lasing wavelength. The typical optical communication wavelength is around 1310 nm, and the corresponding period is 201-207 nm; the laser lasing wavelength is around 1550 nm, and the corresponding period is 238-246 nm. The empty ratio is 0.4-0.6.

The grating width W1 of the apodized grating is 0-2 μm, and the grating width W2 _of the apodized grating is _0.3-7 μm; the grating width W1 refers to the width _of the low refractive index part of the grating _; the grating width W2 refers to the high refractive index of the grating section width.

Each period of the grating consists of two parts, including a high refractive index part and a low refractive index part. In the present invention, the high and low refractive index parts are distinguished by the difference in the grating width, and the widths are W ₂ , W respectively ₁ . The determined grating size corresponds to the determined effective refractive index, thus, the effective refractive index and the grating coupling coefficient can be controlled by controlling the grating width.

The material of the substrate 1 is Si; the material of the buried oxide layer 2 is SiO ₂ , and the thickness is 0.5-3 μm; the material of the waveguide layer 3 is Si, and the thickness is 220-500 nm; Selection of lasing mode. The material of the auxiliary bonding layer 4 is SiO ₂ and the thickness is 0-300 nm; the III-V semiconductor material is adhered to the waveguide layer 3 through the molecular bonding technology of the silicon dioxide dielectric layer. The material of the spacer layer 5 is InP with a thickness of 10-200nm; the material of the cladding layer 6 is SiO ₂ with a thickness of 200-3000nm; the material of the quantum well active region 7 is InAlGaAs or InGaAsP, the thickness is 300-600nm, and the width is 1.5-10 μm; the quantum well active region 7 provides optical gain; the top cladding layer 8 is made of InP, the thickness is 1.4-1.8 μm, the top width is 1.5-10 μm, and the bottom width is 1.5-9 μm; Ohmic contact layer 9 The material is InGaAs, the thickness is 150nm; the material of the P-type electrode 10 is TiPtAu-Au or Ti/Al, the thickness is 200-4000nm; the material of the N-type electrode 11 is TiPtAu-Au or Ti/Al, the thickness is 200-4000nm .

Example 5

A high-power silicon-based semiconductor laser based on an apodized grating according to Embodiment 1, the difference is:

The total length of the apodized grating along the cavity length direction of the resonant cavity is 500 μm, the length of the first uniform region along the cavity length direction of the resonant cavity is 410 μm, the length of the apodized grating along the cavity length direction of the resonant cavity is 20 μm, and the second uniform region is 20 μm long. The length of the region along the cavity length direction of the resonator is 70 μm; the grating period of the apodized grating is 240.3 nm, and the duty cycle of the apodized grating is 0.5; the grating width W1 _of the apodized grating is 0-2 μm, and the The grating width W ₂ is 0.3-7 μm.

The thickness of the substrate 1 is 750 μm; the thickness of the buried oxide layer 2 is 1000 nm; the thickness of the waveguide layer 3 is 400 nm; the thickness of the auxiliary bonding layer 4 is 70 nm; the thickness of the spacer layer 5 is 150 nm; the thickness of the cladding layer 6 is 2000nm; the quantum well active region 7 has a thickness of 400nm and a width of 7μm, the quantum well active region 7 includes three well layers and four barrier layers, arranged in a cross, each well layer has a thickness of 7nm, and each barrier layer has a thickness of 7nm. The thickness of the top cladding layer 8 is 1.6 μm, the top width is 4 μm, and the bottom width is 2.5 μm; the thickness of the ohmic contact layer 9 is 150 nm; the thickness of the P-type electrode 10 is 2000 nm; is 2000nm.

Claims (10)

1. a high-power silicon-based semiconductor laser based on apodized grating, is characterized in that, comprises: substrate, buried oxide layer, waveguide layer, auxiliary bonding layer, spacer layer, cladding layer, quantum well active region, A top cladding layer, an ohmic contact layer, a P-type electrode, and an N-type electrode; an apodized grating is etched in the waveguide layer along the cavity length direction of the resonant cavity; by modulating the lateral width of the apodized grating, the effective efficiency of the resonant cavity The refractive index and grating coupling coefficient vary along the cavity length of the resonator. 2 . A high-power silicon-based semiconductor laser based on apodized grating according to claim 1 , wherein, by modulating the lateral width of the apodized grating, the effective refractive index of the resonant cavity and the coupling coefficient of the grating are made along the resonant cavity. 3 . The effective refractive index of the low refractive index part and the high refractive index part of the grating can be selected by adjusting and selecting the appropriate lateral width of the grating.

Thus, the effective refractive index n _eff of the grating and the coupling coefficient k of the grating are selected;

D represents the duty cycle, and λ ₀ is the Bragg wavelength. 3. The high-power silicon-based semiconductor laser based on an apodized grating according to claim 1, wherein the resonant cavity is sequentially divided into a first uniform area, an apodized area and a second uniform area from left to right, In the first uniform region and the second uniform region, the grating coupling coefficient and the effective refractive index remain unchanged; in the apodized region, the grating coupling coefficient and the effective refractive index change linearly. 4 . The high-power silicon-based semiconductor laser based on an apodized grating according to claim 3 , wherein the effective refractive index of the first uniform region is set to be n _eff1 and the grating coupling coefficient k ₁ ; the second uniform region is effective The refractive index is n _eff2 , the grating coupling coefficient k ₂ ; the grating coupling coefficient in the apodized region changes linearly from k ₁ to k ₂ , and the effective refractive index changes linearly from n _eff1 to n _eff2 ; Assuming that the lengths of the first uniform region, the apodized region, and the second uniform region are l ₁ , l ₂ , and l ₃ respectively, and the distance from a certain position of the apodized region to the leftmost end of the resonator is z, 0<z<l ₁ +l ₂ +l ₃ , the apodized region grating coupling coefficient distribution k(z) and effective refractive index distribution n _eff (z) are expressed as equations (I) and (II):

The optimal n _eff1 , n _eff2 , k ₁ , and k ₂ are determined through simulation, so that the output light can obtain the optimal SMSR, the highest output optical power and a smooth light field distribution. 5 . The high-power silicon-based semiconductor laser based on an apodized grating according to claim 3 , wherein the total length of the apodized grating along the cavity length direction of the resonator is 300-1000 μm, and the first uniform region is 300-1000 μm. 6 . The length of the cavity length direction of the resonant cavity is 200-900 μm, the length of the apodized region along the cavity length direction of the resonant cavity is 5-50 μm, and the length of the second uniform region along the cavity length direction of the resonant cavity is 30-200 μm. 6 . The high-power silicon-based semiconductor laser based on an apodized grating according to claim 1 , wherein the duty ratio of the apodized grating is 0.4-0.6. 7 . 7 . The high-power silicon-based semiconductor laser based on an apodized grating according to claim ₁ , wherein the grating width W1 of the apodized grating is _0-2 μm, and the grating width W2 of the apodized grating is 0.3 μm. 8 . -7 μm; grating width W ₁ refers to the width of the low refractive index portion of the grating; grating width W ₂ refers to the width of the high refractive index portion of the grating. 8 . The high-power silicon-based semiconductor laser based on an apodized grating according to claim 1 , wherein the total length of the apodized grating along the cavity length direction of the resonant cavity is 500 μm, and the first uniform region is along the resonant cavity. 9 . The length of the cavity length direction is 410 μm, the length of the apodized region along the cavity length direction of the resonant cavity is 20 μm, the length of the second uniform region along the cavity length direction of the resonant cavity is 70 μm; the grating period of the apodized grating is 240.3 nm, The duty cycle of the apodized grating is 0.5; the grating width W1 _of the apodized grating is 0-2 μm, and the grating width W2 of the apodized grating is _0.3-7 μm. 9 . The high-power silicon-based semiconductor laser based on an apodized grating according to claim 1 , wherein the material of the substrate is Si; the material of the buried oxide layer is SiO ₂ , and the thickness is 0.5-3 μm; the material of the waveguide layer is Si, the thickness is 220-500nm; the material of the auxiliary bonding layer is SiO ₂ , the thickness is 0-300nm; the material of the spacer layer is InP, the thickness is 10- 200nm; the material of the cladding layer is SiO ₂ , the thickness is 200-3000nm; the material of the quantum well active region is InAlGaAs or InGaAsP, the thickness is 300-600nm, the width is 1.5-10μm; the top cladding layer The material is InP, the thickness is 1.4-1.8μm, the top width is 1.5-10μm, and the bottom width is 1.5-9μm; the material of the ohmic contact layer is InGaAs, the thickness is 150nm; the material of the P-type electrode is TiPtAu -Au or Ti/Al, with a thickness of 200-4000 nm; the material of the N-type electrode is TiPtAu-Au or Ti/Al, with a thickness of 200-4000 nm. 10 . The high-power silicon-based semiconductor laser based on an apodized grating according to claim 1 , wherein the thickness of the substrate is 750 μm; the thickness of the buried oxide layer is 1000 nm. 11 . ; the thickness of the waveguide layer is 400nm; the thickness of the auxiliary bonding layer is 70nm; the thickness of the spacer layer is 150nm; the thickness of the cladding layer is 2000nm; the thickness of the quantum well active region is 400nm , the width is 7μm, the quantum well active region includes three well layers and four barrier layers, arranged in a cross, each well layer thickness is 7nm, each barrier layer thickness is 9nm; the thickness of the top cladding layer The thickness of the ohmic contact layer is 150 nm; the thickness of the P-type electrode is 2000 nm; the thickness of the N-type electrode is 2000 nm.

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